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<head><meta charset="utf-8"><title>A bug related to x32 codegen · t-compiler/wg-llvm · Zulip Chat Archive</title></head>
<h2>Stream: <a href="https://rust-lang.github.io/zulip_archive/stream/187780-t-compiler/wg-llvm/index.html">t-compiler/wg-llvm</a></h2>
<h3>Topic: <a href="https://rust-lang.github.io/zulip_archive/stream/187780-t-compiler/wg-llvm/topic/A.20bug.20related.20to.20x32.20codegen.html">A bug related to x32 codegen</a></h3>

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<a name="161966988"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/187780-t-compiler/wg-llvm/topic/A%20bug%20related%20to%20x32%20codegen/near/161966988" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Charles Lew <a href="https://rust-lang.github.io/zulip_archive/stream/187780-t-compiler/wg-llvm/topic/A.20bug.20related.20to.20x32.20codegen.html#161966988">(Mar 28 2019 at 16:04)</a>:</h4>
<p>There was <a href="https://github.com/rust-lang/rust/pull/55431" target="_blank" title="https://github.com/rust-lang/rust/pull/55431">this PR</a> that seems code finished but triggering a suspected LLVM bug. It occurs on the gnux32 target. I wonder if any one's able to give it a look and find a way to fix it or work around it...</p>



<a name="161967001"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/187780-t-compiler/wg-llvm/topic/A%20bug%20related%20to%20x32%20codegen/near/161967001" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Charles Lew <a href="https://rust-lang.github.io/zulip_archive/stream/187780-t-compiler/wg-llvm/topic/A.20bug.20related.20to.20x32.20codegen.html#161967001">(Mar 28 2019 at 16:04)</a>:</h4>
<p>The output is: <code>LLVM ERROR: Cannot emit physreg copy instruction</code></p>



<a name="161974351"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/187780-t-compiler/wg-llvm/topic/A%20bug%20related%20to%20x32%20codegen/near/161974351" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Nikita Popov <a href="https://rust-lang.github.io/zulip_archive/stream/187780-t-compiler/wg-llvm/topic/A.20bug.20related.20to.20x32.20codegen.html#161974351">(Mar 28 2019 at 17:28)</a>:</h4>
<p>There's a similar issue here: <a href="https://github.com/rust-lang/rust/issues/45417" target="_blank" title="https://github.com/rust-lang/rust/issues/45417">https://github.com/rust-lang/rust/issues/45417</a> That one is apparently resolved. What LLVM version were we at when the PR encountered this issue?</p>



<a name="161978440"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/187780-t-compiler/wg-llvm/topic/A%20bug%20related%20to%20x32%20codegen/near/161978440" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Charles Lew <a href="https://rust-lang.github.io/zulip_archive/stream/187780-t-compiler/wg-llvm/topic/A.20bug.20related.20to.20x32.20codegen.html#161978440">(Mar 28 2019 at 18:13)</a>:</h4>
<p>Definitely before the llvm 8 update: <a href="https://github.com/rust-lang/llvm-project/commits/683d3522690b7a9d0163e7e7e6586f2b1364ed02" target="_blank" title="https://github.com/rust-lang/llvm-project/commits/683d3522690b7a9d0163e7e7e6586f2b1364ed02">https://github.com/rust-lang/llvm-project/commits/683d3522690b7a9d0163e7e7e6586f2b1364ed02</a></p>



<a name="162010706"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/187780-t-compiler/wg-llvm/topic/A%20bug%20related%20to%20x32%20codegen/near/162010706" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Charles Lew <a href="https://rust-lang.github.io/zulip_archive/stream/187780-t-compiler/wg-llvm/topic/A.20bug.20related.20to.20x32.20codegen.html#162010706">(Mar 29 2019 at 02:13)</a>:</h4>
<p><a href="https://github.com/rust-lang/rust/pull/59500" target="_blank" title="https://github.com/rust-lang/rust/pull/59500">Rebased the PR to master</a>. It seems the tests pass now.</p>



<a name="162027439"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/187780-t-compiler/wg-llvm/topic/A%20bug%20related%20to%20x32%20codegen/near/162027439" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Nikita Popov <a href="https://rust-lang.github.io/zulip_archive/stream/187780-t-compiler/wg-llvm/topic/A.20bug.20related.20to.20x32.20codegen.html#162027439">(Mar 29 2019 at 08:32)</a>:</h4>
<p>The try build only tests a single configuration, while the previous failure was on dist-various-2, so this doesn't really tell us whether the issue is resolved or not.</p>



<a name="162057848"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/187780-t-compiler/wg-llvm/topic/A%20bug%20related%20to%20x32%20codegen/near/162057848" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Charles Lew <a href="https://rust-lang.github.io/zulip_archive/stream/187780-t-compiler/wg-llvm/topic/A.20bug.20related.20to.20x32.20codegen.html#162057848">(Mar 29 2019 at 15:51)</a>:</h4>
<p>oh!! sorry i'm not familiar with this, but if there any way to ask bors to test it on gnux32?</p>



<a name="162311178"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/187780-t-compiler/wg-llvm/topic/A%20bug%20related%20to%20x32%20codegen/near/162311178" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Charles Lew <a href="https://rust-lang.github.io/zulip_archive/stream/187780-t-compiler/wg-llvm/topic/A.20bug.20related.20to.20x32.20codegen.html#162311178">(Apr 02 2019 at 07:49)</a>:</h4>
<p>A <code>dist-various-2</code> run reveals that the problem is still there :(</p>



<a name="162490361"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/187780-t-compiler/wg-llvm/topic/A%20bug%20related%20to%20x32%20codegen/near/162490361" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Charles Lew <a href="https://rust-lang.github.io/zulip_archive/stream/187780-t-compiler/wg-llvm/topic/A.20bug.20related.20to.20x32.20codegen.html#162490361">(Apr 04 2019 at 03:12)</a>:</h4>
<p>Minimized the case to <a href="https://github.com/rust-lang/rust/issues/59674" target="_blank" title="https://github.com/rust-lang/rust/issues/59674">https://github.com/rust-lang/rust/issues/59674</a></p>



<a name="163756791"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/187780-t-compiler/wg-llvm/topic/A%20bug%20related%20to%20x32%20codegen/near/163756791" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Nikita Popov <a href="https://rust-lang.github.io/zulip_archive/stream/187780-t-compiler/wg-llvm/topic/A.20bug.20related.20to.20x32.20codegen.html#163756791">(Apr 19 2019 at 19:00)</a>:</h4>
<p>Submitted <a href="https://reviews.llvm.org/D60909" target="_blank" title="https://reviews.llvm.org/D60909">https://reviews.llvm.org/D60909</a> to fix this issue.</p>



<hr><p>Last updated: Aug 07 2021 at 22:04 UTC</p>
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